Dyshidrosis (Dyshidrotic Eczema)

What dyshidrosis looks like

• tiny (1 to 2 mm), deep-seated blisters that look like tapioca or sago grains under the skin
• mainly on the sides of the fingers, palms and soles
• intense itching or burning, often starting before blisters appear
• blisters may merge into larger blisters
• after 1 to 3 weeks, blisters dry and the skin peels, cracks and becomes rough
• repeated flares can cause thickened skin and nail changes (ridges or pitting)

Despite the name, which means "difficult sweating", dyshidrosis is not caused by blocked sweat glands. It is a form of eczema, though sweaty hands make it worse.

Causes and triggers

The exact cause is unknown. Factors linked to flares include:

• atopic dermatitis, hay fever or asthma, either personal or family history
• sweaty hands and feet (hyperhidrosis), hot weather and humidity
• emotional stress
• metal allergies: nickel and cobalt in jewelry, coins, tools and some foods
• wet work and irritants: frequent handwashing, detergents, solvents, cement
• fungal infection on the feet (athlete's foot), which can trigger blisters on the hands as an "id reaction"
• IV immunoglobulin treatment in some people
• smoking

Conditions that look similar

Diagnosis

A dermatologist usually diagnoses dyshidrosis by its appearance and history. Tests may include:

• skin scraping for fungus on the hands and feet
• patch testing to find contact allergies such as nickel, cobalt, fragrances or rubber chemicals
• swab if infection is suspected
• biopsy rarely, when the diagnosis is unclear

Treatment

Skin care and trigger avoidance

• Wash hands with lukewarm water and a soap-free cleanser, then dry gently.
• Apply a thick, fragrance-free moisturizer or ointment after every wash and often during the day.
• Wear cotton-lined waterproof gloves for wet work and cleaning.
• Remove rings before washing hands.
• Keep hands and feet cool and dry. Change socks often.
• Avoid nickel and cobalt if you are allergic. A low-nickel diet helps some people with proven nickel allergy.
• Treat athlete's foot.

Calming a flare

• Cool compresses or soaks for 15 minutes, a few times a day. Potassium permanganate or aluminum acetate soaks help dry weeping blisters.
• Potent or very potent topical steroids, needed because palm and sole skin is thick. Use as directed for limited periods.
• Do not pop large blisters. A doctor can drain them safely if very painful.
• Antihistamines at night may help sleep, though they do not stop the eczema.

Severe or persistent dyshidrosis

• Topical calcineurin inhibitors (tacrolimus, pimecrolimus) and topical JAK inhibitors such as delgocitinib cream for chronic hand eczema
• Phototherapy (PUVA or UVB) of the hands and feet
• Short courses of oral steroids for severe flares
• Oral alitretinoin (in some countries) or other immune-modulating medicines such as methotrexate, ciclosporin or dupilumab
• Botulinum toxin injections or iontophoresis for excessive sweating that triggers flares

Outlook

Dyshidrosis is a long-term condition for many people, with flares that come and go, often in warmer months. With good skin care and trigger control, most people keep it manageable. Some find it fades over years.

Frequently asked questions

What causes dyshidrosis?

The exact cause is unknown. Flares are linked to atopic eczema, sweaty hands and feet, heat, stress, nickel or cobalt allergy, frequent wet work and fungal infections. It is not contagious and is not caused by blocked sweat glands.

How do I get rid of dyshidrotic eczema fast?

Use cool soaks to soothe itching, a potent steroid cream prescribed by your doctor, and frequent moisturizers. Avoid triggers such as wet work and metal contact. Most flares settle in 2 to 4 weeks, faster with treatment.

Should I pop dyshidrosis blisters?

No. Popping blisters increases the risk of infection and irritation. Let them dry on their own. If large blisters are very painful, a doctor can drain them safely with a sterile needle.

Is dyshidrosis contagious?

No. Dyshidrosis is a type of eczema and cannot spread to other people. However, it can be confused with contagious conditions like scabies or fungal infections, so see a doctor if you are unsure.

Does stress cause dyshidrosis?

Stress is a common trigger for flares in people prone to dyshidrosis, but it is not the only cause. Heat, sweating, metal allergies and wet work also play major roles. Managing stress can reduce how often flares occur.